


Plan Omega

by slytherclawgurl



Category: Harry Potter - J. K. Rowling
Genre: Adult Hermione Granger, Albus Dumbledore Bashing, Albus Dumbledore Being an Idiot, Bad Albus Dumbledore, Character Bashing, Evil Voldemort (Harry Potter), First War with Voldemort, Good Severus Snape, Hermione Granger & Harry Potter Friendship, James Potter Bashing, James Potter Being an Asshole, Lily Evans Potter & Severus Snape Friendship, Manipulative Albus Dumbledore, Marauders Era (Harry Potter), Minor Lily Evans Potter/Severus Snape, No Horcruxes, Pureblood Harry Potter, Pureblood Hermione Granger, Pureblood Lily Evans Potter, Ravenclaw Hermione Granger, Teacher Harry Potter, Time Travel, Young James Potter, Young Lily Evans Potter, Young Peter Pettigrew, Young Severus Snape, Young Sirius Black
Language: English
Status: In-Progress
Published: 2021-02-05
Updated: 2021-02-05
Packaged: 2021-03-17 06:00:00
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,791
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/29220612
Author URL: https://archiveofourown.org/users/slytherclawgurl/pseuds/slytherclawgurl
Relationships: Hermione Granger/Harry Potter, Lily Evans Potter/Severus Snape, Regulus Black/Marlene McKinnon
Kudos: 33





	1. Apocalypse

Hermione Granger and Harry Potter’s world was over. The people they knew were gone, either dead or lost in their trauma. They were the only one left. They had all suffered, but she was the only one who was still herself. Ron had been killed by Greyback, saving Lavender Brown. Remus Lupin and Tonks were dead, George Weasley had killed himself to join his twin, right after leaving them all his memories and inventions. Fred and Gearge had been the smartest people ever, not that theri genius was known as anything other than post mortem. Molly and Arthur were depressed, and Hermione’s own parents had died in a plane crash. Neville was missing, and Luna moved to America, with her boyfriend, Rolf Scamander. McGonagall had lost her vocal chords, Flitwick had moved back with his goblin father after his witch mother and sister had died in a death eater raid. Everyone else they were close to was either scarred beyond belief, gone out of the country, or no longer alive to leave it  
There was nothing left to stay for. There was only one thing they could do.   
Use the research notes Luna, Fred, and George had left. Those three working together had accomplished what centuries of unspeakables could not. Permanent, long term time travel. NOw Harry and Hermione had to just choose a year, month, and day. The device was non-reusable and set to self-destruct along with the notes. The knowledge would die with them, and thanks to an ancient spell on the knowledge, nobody would be able to discover it again, unless it was necessary to save the world from collapsing in on itself.   
It already had. The statue of secrecy was broken, the muggle witch-hunter extremists could pound down the door any day. The world seemed to think that Britain needed to be eliminated, and magical populations worldwide were at an all time low. Four and a half thousand witches and wizards. That was it. The only other time human populations were so low was millions of years ago when humans nearly went extinct*.  
So Harry and Hermione pressed their fingers into the device, wands long since gone. August 1st, 1976. Hermione double checked, She had packed. All of the people who knew Plan Omega had willed everything to her. They needed all the advantages she could get. Blood adopted into as many families as they could, to use their family magic, an advantage they discovered too late. Money, billions of galleons, more than anyone had ever had at once. Not that it could bring people back. Fred and George’s technology and notes, Luna’s visions, Notes about the entire timeline, full descriptions of anyone and everyone they could, memories, stored. Documents created. Information learned. They would have to be on a level with some of the most powerful people of the generation. Hogwarts wouldn’t know what hit it. Harry and Hermione was coming, and they were ready for anything fate, that cruel bitch, could toss.


	2. Arrival at Hogwarts

August 14th, 1975  
Albus Dumbledore was both curious and worried about meeting his new teachers. Hermione Ravenclaw and Harold Gryffindor. Graduates of Myrddin Emrys Academy of Magic in Switzerland, all honors, from the most elite magic school in the world. Impossible to forge their documents, none but elite upstanding citizens every graduating, seven students every year, from all over the world. Secrecy of the highest level.  
The guardian to his office swung open, the pair walking in. Harold Gryffindor was a tall, strong man in his mid-twenties, dark black hair with a hint of coppery red laying smoothly on his head, eyes the color of the killing curse glowing softly like emerald coals. He was dressed in orange robes, not for any house, yet still in line with his heritage.  
Hermione Ravenclaw was a beautiful young lady, also in her mid-twenties. She wore violet robes to match her eyes which were softly glowing like Harold’s. Her hair was a golden brown color, cascading down her back in soft waves. Her left hand’s ring finger also had a beautiful engagement ring, which judging by the chaste kiss the two shared before walking in, was from Mr. Gryffindor.  
“Mr. Gryffindor, Ms. Ravenclaw, pleace, sit down. Lemon drop?”  
“No thank you. I find I don’t like muggle sweets, especially those laced with loyalty potion, truth compulsion potion, and a calming draught in near illegal amounts. My occlumency shields are good, but I do like to keep my mind my own.”  
Dumbledore sputtered at Gryffindor’s response. He calmed himself, and continued. “Yes, well, I see you are applying for the positions of Defense Against the Dark Arts and Head of Gryffindor, Mr. Gryffindor?”  
“I thought it fitting, seeing as my ancestor was the first. I heard your current Head of Gryffindor was also Transfiguration Professor and Deputy Headmistress. She could probably use a lighter load.”  
“Yes, yes, of course.”  
“Oh.” They both lifted their left sleeves, bare skin on both. “Just to assure those doubts.”  
“And Miss Ravenclaw, you wish to implement and teach Ethics class?”  
“Your students need it. I’ve seen how some of your graduates either are scared to do anything past a simple summoning charm, while others use the darkest of curses on innocents. I can do Head of any of the other three houses, as Lady of House Ravenclaw, as well as Lady of House Slytherin, I know you are thinking it, I left the Gaunt insanity and inbreeding six generations in the past, Harry eight. Although Salazar’s Parselwards do need some maintaining, and we are both parselmouths, and trained in the arts. The reason we went to Emrys and not here. I am of no relation to House Hufflepuff past the normal interbreeding of the wizarding world, but Hufflepuffs are notoriously peaceful and easy to negotiate with and take care of, past the usual teen gossip”  
“Yes, yes, of course. But those are already taken care of. However, I must say, the class is a very good idea, and I do think both of you will make marvelous additions to the staff.”  
“Headmaster? We are engaged, as were wondering if joint quarters, without gossiping portraits, only a password on a stretch of wall, would be possible?” For more reasons than you may think, thought Harry.  
“Yes, of course. Three hallways down from the great hall and to the right.”  
The next weeks passed peacefully, both new teachers settling into their rooms, only staying at the school overnight, the rest of the day noticeably absent.  
When September First came around and Slughorn had potentially volatile potions brewing and Hagrid was down with the flu, the two new professors were asked to ride the train with the students, later guiding them across the lake.  
***  
Lily Evans pushed past those jerks, Potter and Black. Lupin and Pettigrew were alright, but they never left the marvelous jerk duo. Her best friend, Severus Snape, trailing behind her. (A./N I like to think that with magic the Hogwarts express hallways would be a lot wider than in the movie, and the compartments self-expanding. They couldn't do it in the movie, but I can do it here, so just to clear up confusion) Potter’s shoulder ‘accidentally’ met Severus’ gut, and Lily whirled on him, her wand between his eyes. Her wand tip started to glow as she forced magic through it, silently, until her wand flew out of her hand. She turned in the direction her wand had flown, along with those of Severus, Black, and Potter. The person with their wands was in his mid twenties, with very dark red hair and emerald eyes, shining stronger even than Lily’s own. Next to him walked up a woman of the same age, with smooth golden brown hair and violet eyes shining like the man’s.  
The man turned his sharp gaze to Potter. “Ten points from Gryffindor for harassment of fellow students,” He turned back to Lily, “And Evans, be glad I disarmed you, sending a curse at a fellow student would have gotten you detention before the year started, defense of a friend or not.” He sighed. ”And I thought by OWLs these kids would be more mature,” he mumbled, not even bothering to lower his voice.  
The students left to find their own compartment, most correctly guessing who the teacher was. Slughorn obviously couldn’t supervise the train ride that year, so this teacher, no doubt the new DADA professor was on the train, and seemingly brought his girlfriend. Lily, on the other hand, was lost in thought on another topic. She had researched it the previous year, and knew that al magical families had a distinctive trait, for example Potter’s untameable hair, Malfoy’s platinum blonde, Weasley’s distinctive red mop, Severus’ mother’s family, the Prince family’s obsidian black eyes, Dumbledore’s twinkling blue eyes, etcetera. She had even done a blood test at Gringotts, but since she wasn't a Head of House, all she got was an answer that her mother was from a squib line, and that her Head of House had been notified. And this professor’s striking green eyes had reawakened that curiosity.  
When Lily's other best friend, Ravenclaw Marylin Balckwell, came into their compartment, the Hogwarts gossip queen’s patience had worn out, she turned to Severus, “What’s got her so contemplative? Potter do something to mess with her mind again?”  
“Not this time. New professor, the same family trait, same eyes.”  
Lily huffed. “I don’t know! It’s so confusing. Should I ask him? Would it be strange? Ugh!”  
Marylin just stared. “Did your beloved common sense just leave? Wait until the feast when his name’s announced. Maybe it turns out that’s your grandmother’s maiden name or something, and you didn’t even know it was a wizarding family. You said you found out you're from a squib line, maybe he knows which family it’s from. I mean, the goblins said that you’re not a Head of House, but whoever’s Head of House has been told there’s a member of their family, maybe that’s the professor's parent.”  
“Yes, of course.” They switched to other, more lively topics such as debating who the other prefects would be that year. In the end, they decided it would have to be Alice Fortescue and Remus Lupin, although Dumbledore may have chosen Alice fortescue just because her grandfather invented Drooble’s Best Bubble Gum, and her uncle ran Fortescue’s ice cream parlor. Dumbledore was way too obsessed with his sweets.  
***  
After the new first years were sorted, no big surprises except one little firstie named Gilderoy Lockhart who would not stop boasting, Albus Dumbledore stood up for his annual sorting feast speech.  
“Now, to our new students, welcome, to our old students, welcome back! Another year full of magical education awaits you. Now, I have some start of term announcements to make. First of all, the Forbidden Forest is just that. Secondly, let me introduce some teaching changes. First of all, our Defense Against the Dark Arts professor for this year. Please welcome Professor Harold Gryffindor. As Professor McGonagall has a very large workload, she is stepping down as Head of Gryffindor House, the position now taken by Professor Gryffindor. Furthermore, we also have a new mandatory class for all years. There will be no OWLs or NEWTs to this class, but it is no less important in these dark times. Please welcome Professor Hermione Ravenclaw, teaching our new Ethics class.”  
Murmurs were spreading through the students like wildfire. The Gryffindors were sitting up straighter. They had the heir of Gryffindor as their Head of House. The Ravenclaws were planning on finding out the location of Professor Raenclaw’s office to ask her about Rowena’s legendary library that has every book in existence, including copies of the Founder’s journals. The Slytherins were speculating about the prejudices of both new teachers, especially considering one was a Gryffindor, literally, and the other was teaching ethics. The Hufflepuffs were just busy eating and gossiping. The usual.  
The rest of the feast held no more surprises.  
Whispers, on the other hand, were everywhere around the hall. At the end of the feast, the Gryffindor table heard Sirius Black’s annual shout of, “Come on, I’m taking bets for how the defense curse will act up this year!”  
People started coming up with the galleons, and Sirius started announcing it. “A galleon on getting mauled by an acromantula. Ten sickles on getting bitten by a werewolf. Two galleons on getting killed with the instant death curse by death eaters, specific.”  
Professor Gryffindor came up to Sirius Black with a sack of Galleons. “A hundred galleons on the only thing I’m leaving for is to get married, but I will be right back. You are not getting rid of me that easily. The acromantula are too scared to harm a parselmouth, or the fiancee of one with a dormant basilisk beneath the school, and a werewolf is absurdly easy to deal with when you have an animagus form larger than said werewolf.” He looked pointedly at Sirius Black, flicking his eyes at Remus Lupin, then at a piece of dog hair on Sirius’ bag. His eyes widened and Gryffindor smirkedRemus Lupin also noticed, and, carefully watching the marauder’s map, to check whether Professor Gryffinddor was who he said he was, saw his name was in strange unidentifiable runes. Below it was a note: Messer. Chimera says don’t forget parselmagic powers and control the Hogwarts Wards. I don’t tolerate bullies. Remus’ eyes widened and he passed the map to James, Peter, and Sirius. How in the world had he tampered with it?  
***  
The next morning, as Gryffindors were sleepily piling into their common room, Professor Gryffindor came in, vials of disgusting smelling potion passed around. “If you can’t wake up, at least take some pepper up potion,” His charges gratefully gulped down the noxious concoction.  
“Professor? What are you doing here? We didn’t meet Professor McGonagall until she handed out schedules.” a second year asked.  
“I was informed by Professors Flitwick and Sprout that they usually hold a short house meeting in the mornings before leading the students to the Great hall.”  
The questions rushed at him.  
“You didn’t go to Hogwarts, did you? Then how do you know the way to the Great Hall?”  
“Can you provide pepper up potion every morning?’  
“Are you changing anything else McGonagall had in place?”  
Professor Gryffindor sent a wide area silencing charm at the Gryffindors. “One thing at a time. Yes, I know the way to the Great hall. I would be pretty useless as a teacher if I didn’t know my way around. As for pepperup potion, I have found it is one of the most useful potions ever, especially considering it isn’t addictive like other more useful potions, including dreamless sleep. I will not be brewing it regularly, but Professor Skughorn has agreed that it is an essential potion to be able to brew like the back of our hand. It takes only a half an hour, and everyone who can brew the potion to an O level during your free time, of course under Professor Slughorn’s supervision, will get extra credit for me, and the potion will go to your fellow housemates, you can spread that around, that applies to all houses.  
As for changing anything Professor McGonagall had in place, I don’t know what rules she had. I will say it once, I don’t give preferential treatment. And if I hear any slurs, you will get detention. I only take house points for class related things, because I know how ineffective they are. I went to LeFay Academy, I was in the same year as Professor Ravenclaw, and we had a similar system, but individual points. It got abolished in my second year.”  
Harry was mentally thanking Hermione ramming their backstory into his brain. He would need to let certain harmless details slip once in a while, but details that would stop people from digging too deeply.  
Several students looked like they were about to burst with questions. “Alright. For those of you with questions, ask them on the way to the Great Hall. If I don’t get to you, write them down and pin them on the second announcement board.” They looked, and there was, in fact, a second announcement board there. “Lastly, some of you will need this more than most. I don’t tolerate bullying. I heard from McGonagall which pranksters her grey hairs come from, and I will be looking at you. I do have a sense of humor, prank the whole school with pink hair if you want, but nothing harmful or targeting a specific person or group of people. If you want revenge so badly, call them out for a public duel. I’ve placed a dozen copies of the school charter on that table,” he pointed to a table with several large books, “None of you have the excuse of never having seen it.”  
He then led them to the Great Hall, answering questions all the way. Yes, he could do wandless magic. Yes, he would teach them. No, Gryffinddor didn’t have any secret chamber like slytherin that he knew of. No, he did not know whether or not Dumbledore was sane. No, he would not assign detentions with Filch. And on and on.  
Reaching the great hall, the conversations broke up, and Harry headed up to the staff table, his unbreakable occlumency making sure he didn’t kill Peter, hug Lily, or act like he knew these kids. These were not the same people who his history knew, and he was going to make sure of it.  
When he sat up at the staff table, between McGonagall and Slughorn, the deputy headmistress remarked, “The students seem to like you.”  
“Offering them all pepperup potion and promising not to send their detentions to Filch except for the worst offenses can do wonders.”  
Slughorn looked shocked. “Peperup is addictive, you do know that?”  
Harry reached into a small pouch he had around his wrist, and stated, “peperup recipe,” A sheet of parchment flew out. “It’s not.” he geminoe’d his parchment and handed a copy to Slughorn. “At least this version isn’t. The one in their textbooks is insanely complicated and is addictive. This version isn’t. This is the one I learned to brew. No moondew required, makes it much easier, and only takes a half hour.”  
Slughorn gaped. “This is so much more effective. Where did you learn to brew like this?”  
“School,” Harry deadpanned. “I did have the qualifications to become an auror, and would have been one, until I applied and realized the sheer amount of rules, regulations, and legal technicalities I would be bound by. Then Hermione suggested applying at Hogwarts, which seems to be in need of a new Defense professor every year lately. Since the class of ‘45 graduated, I think, Headmaster?”  
Slughorn nearly choked, while Dumbledore paled a little. Was it possible this stranger knew his second biggest secret. Harry turned to Hermione, sitting next to him, and whispered something. Except when Hermione’s eyes lit up in humor, and she whispered back, did Slughorn and Dumbledore realize that the two were not in fact whispering. Slughorn did, in fact, actually choke on his crystallized pineapple when he recognized he was hearing Parseltongue for the first time in thirty years. Harry sighed, hissed something to Hermione, who sighed then chuckled, and then turned back to Slughorn.  
“Are you alright Professor Slughorn?  
“Yes, Yes.” he exchanged a look with Dumbldore, who then asked the pair to accompany him to his office.  
“Mister Gryffindor, or should I say, Tom?”  
“Professor Dumbledore, what are you talking about?”  
“You were not born Hadrian Gryffindor, were you?”  
“No.”  
“I knew it. Cut the charade Mister Riddle”  
“Riddle? Ithink I heard the Headmaster complaining about a Tom Riddle that kept begging to be accepted back in my third year. One student transferred out to America, either Ilvermorny or Salem, and he was nearly accepted, except his magical guardian said that he needed to be watched or something of the sort.”  
“Only something Tom would know. But I guess you don't respond to that name, anymore, do you Voldemort?”  
Harry glared at the headmaster. “For your information I was born Hadrian Ignotus Peverell, but changed it to gryffindor, from whom i am also descended when I realized I would never get away from fanboys that keep asking me to hand over family artifacts, or claiming to be my family’s master because they have a wand made from elder, a stone with some runes carved on it, or an invisibility cloak that lasts more than a year. Potter’s probably going to be one of them, they claim to have the cloak every single generation.” Harry sighed.  
“No, that’s not possible. The only remaining parselmouth was Tom, and you must be his daughter or something. I know that you were always good at disguising magic, Tom.”  
Harry was now officially pissed. “You dare accuse me of parading around as the man who killed my best friend and a girl who was my sister in everything but blood? Whose actions directly caused the deaths of two people who were like parents to me?” Harry wasn’t just pissed. He was mad. He had finally let go of some of his aura, and it was pushing Dumbledore and Slughorn down into their chairs as if they were being trampled by a herd of hippogriffs. “You accuse me of being in an incestuous relationship, of countless murders and ordering even more, because of what? A magical talent and a suspected ancestor who got on the wrong side of another one of my ancestors and went down as the loser in History?”  
“What do you mean? Slughorn stuttered out weakly  
Hermione explained, “The founders were all very good friends, and defeated the dark lord at the time, Herpo the Foul. But then years later, when Hogwarts was up and running in Rowena’s ancestral castle, wards powered by Salazar’s parselmagic, Sorting hat created by helga to last millenia, and Helga’s familiar, a phoenix, guarding the castle and those inside it, Salazar and Godric had an argument. It escalated into a full scale duel. You know what it was about? A girl. The right to ask Ignotus Peverell III to court his daughter. She ended up marrying Corvin Gaunt in the end. Her second son, who took up the Peverell name, inherited it from his grandfather, married Gryffindor's daughter. And their great grandson married Salazar's great-granddaughter, and their great-granddaughter married Rowena’s grandson, whose father was Salzar’s apprentice. I am descended from the latter, Harry from the former.”  
While Dumbledore and Slughorn were gaping with their mouths wide open, Harry and Hermione left to go teach their first classes.

**Author's Note:**

> A/N Please note that I will be updating completely randomly, and may or may not have more written. I am more regular and active on FFN, under the username slytherinlibrarymole https://www.fanfiction.net/u/13991594/ I have a Grey! Harry and MCOC story there, books time period. I will only post another story there when I am done with that one, which will take a while.


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